Condensate drain lines are widely employed for air conditioning and refrigeration systems. It is not uncommon for these and other types of drain lines to occasionally become partially or completely clogged with debris. Unfortunately, conventional techniques for servicing and unclogging such drain lines have proven to be time consuming and tedious. Typically, such cleaning is performed by introducing, into one end of the line, a pressure that is sufficient to clean out the line and/or remove any blockages therein. Often the service person must gain access to the upper end of the condensate line proximate the air conditioner or refrigeration system so that pressure may be applied at that end. This can be difficult when the unit is located in a small or confined space or is otherwise inconveniently placed, such as in an attic. Moreover, considerable time may be required for servicing, as the upper end of the line must be detached from the air conditioner or refrigeration system and then replaced when the maintenance is completed. Alternatively, the service person may have to cut the line to introduce pressure at an intermediate point. In addition to taking considerable time, this method requires use of a cutting tool and damages the drain pipe, which must then be required or replaced when the servicing is completed.
Because of the time and effort involved in the above techniques for cleaning drain conduits, such service typically tends to be fairly expensive. There is a known device wherein pressure for cleaning or maintaining a conduit is applied through a three-way valve to a section of plumbing located either above or below a separate gate valve in the plumbing. This device is generally intended for use with indoor plumbing fixtures only, and requires the use of a pair of rather intricate and expensive valves. If either of the valves fails, the system is rendered inoperable. Moreover, this known apparatus is intended only for removing blockages from the drains through the application of a positive pressure. The device is not designed for routinely maintaining the pipes to remove debris, which may collect over time to form a blockage.